class klass{
    constructor(number){
        this.number = number;
    }
    assignLeader(student){
        if(student.klassObj.number == this.number){
            this.leader = student;
        }else{
            console.log('It is not one of us.');
        }
    }
    appendMember(student){
        student.klassObj = this;
    }
    isIn(student){
        return (student.klassObj.number === this.number) ? true : false;
    }
}

module.exports.klass = klass;